Although reps for the couple won’t comment, Us Weeklyreports that although Nina and Ian have broken up, they remain “consummate professionals” and “will continue to work together and remain best friends, which is where the relationship started.”

After news broke on Thursday, Ian cryptically tweeted, “A THOUGHT FOR TODAY: People change and forget to tell each other.”

Nina told Seventeen magazine last year that she never intended to get involved with a co-star. “My goal on the show was to be professional, but sometimes you can’t help who you have a connection with, and you can only fight it for so long — which I did for a really, really long time.”

The Vampire Diaries is currently in its fourth season and will begin filming its fifth in the fall.